The overall objective of this project is to obtain a better understanding of molecular evolution as it applies to multi-subunit enzymes via a detailed study of four related enzymes from a Pseudomonas species (NAD ion linked 3-amino propanal, 4-aminobutanal and succinic semialdehyde dehydrogenases, NADP ion dependent succinic semialdehyde dehydrogenase). Determination of the immunogenic, catalytic, subunit-interaction and finally amino acid sequence relationships that exist between these enzymes will allow testing of current models of enzyme evolution. BIBLIOGRAPHIC REFERENCE: Tchen, T. and Callewaert, D., Evolution of the Immunogenic and Subunit Interaction Sites of Oligomeric Enzymes, in Z. A. Atassi (ed.) Immunochemistry of Proteins, V. II, Plenum, New York (1977) in press.